GCSE AQA Triple Biology Higher Tier Paper
2 with perfect answers
Homeostasis - Ans>>The regulation of the internal conditions of a cell or organism
in response to internal or external changes. E.g. the control of: blood glucose
concentration, body temperature, water and ion levels, etc.
Negative Feedback - Ans>>This is a type of control mechanism:
1) a receptor detects a change in a stimulus.
2) the coordination centre compares the stimulus to a set point.
3) an effector then produces a response to correct any difference from the set point.
The Thermoregulatory Centre - Ans>>This is in the brain and it monitors and
controls body temperature, blood temperature via impulses from temperature
receptors.
Effects when Body Temperature is too High - Ans>>- Vasodilation.
- Swear more.
- Transfer of energy form the skin to the environment.
Effects when Body Temperature is too Low - Ans>>- Vasoconstriction
- Stop sweating
- Piloerection
- Shiver
The Nervous System - Ans>>This enables humans to react to their surroundings
and coordinate their behaviour. It stimulates a reflex arc.
Types of Neurones - Ans>>Sensory Neurone, Motor Neurone, Relay Neurone.
Reflex Arc - Ans>>1) the pain stimulus is detected by receptors.
2) impulses from the receptor pass along a sensory Neurone to the CNS.
3) an impulse then passed through a relay Neurone.
4) a motor neurone carries an impulse to the effector.
5) the effector (muscle or gland) responds
Synapse - Ans>>The connection between neurones. When an electrical impulse
reaches this, a chemical is released that diffused across the gap. This causes an
electrical impulse to be generated in the second one.
, Human Reaction Time Required Practical - Ans>>1) the experimenter holds a meter
rule from the end.
2) the subject had their finger and thumb a small distant apart either side of the
ruler on the 50cm line.
3) the experimenter lets go of the ruler and the subject has to trap it.
4) the distance the ruler travels from the 50cm line is noted.
5) the experiment is repeated on the subjects that have just drunk coffee and the
subjects that have not.
Parts of the brain - Ans>>- Medulla
- Cerebellum
- Cerebral Cortex
Medulla - Ans>>controls automatic actions such as heartbeat and breathing.
Cerebellum - Ans>>coordinates movement and balance
cerebral cortex - Ans>>responsible for consciousness, intelligence, memory and
language.
Parts and Functions of the Eye - Ans>>- Retina - contains receptor cells that are
sensitive to brightness and colour of light.
- Optic Nerve - carries impulses from the retina to the brain.
- Sclera - forms a tough outer layer.
- Cornea - transport region.
- Iris - controls the size of the pupil and the amount of light reaching the retina.
- Ciliary Muscles & Suspensory Ligaments - change the shape of the lens to focus
light onto the retina.
Accommodation - Ans>>The process of changing the shape of the lens to focus on
near or distant objects.
Myopia - Ans>>Shortsightedness.
Hyperopia - Ans>>Long sightedness.
The Endocrine System - Ans>>This is made up of glands that secrete hormones
directly into the bloodstream.
Hormones - Ans>>Chemical messengers that are carried in the blood.
Pituitary Gland - Ans>>This is a master gland in the brain that secretes several
hormones in response to body conditions.
2 with perfect answers
Homeostasis - Ans>>The regulation of the internal conditions of a cell or organism
in response to internal or external changes. E.g. the control of: blood glucose
concentration, body temperature, water and ion levels, etc.
Negative Feedback - Ans>>This is a type of control mechanism:
1) a receptor detects a change in a stimulus.
2) the coordination centre compares the stimulus to a set point.
3) an effector then produces a response to correct any difference from the set point.
The Thermoregulatory Centre - Ans>>This is in the brain and it monitors and
controls body temperature, blood temperature via impulses from temperature
receptors.
Effects when Body Temperature is too High - Ans>>- Vasodilation.
- Swear more.
- Transfer of energy form the skin to the environment.
Effects when Body Temperature is too Low - Ans>>- Vasoconstriction
- Stop sweating
- Piloerection
- Shiver
The Nervous System - Ans>>This enables humans to react to their surroundings
and coordinate their behaviour. It stimulates a reflex arc.
Types of Neurones - Ans>>Sensory Neurone, Motor Neurone, Relay Neurone.
Reflex Arc - Ans>>1) the pain stimulus is detected by receptors.
2) impulses from the receptor pass along a sensory Neurone to the CNS.
3) an impulse then passed through a relay Neurone.
4) a motor neurone carries an impulse to the effector.
5) the effector (muscle or gland) responds
Synapse - Ans>>The connection between neurones. When an electrical impulse
reaches this, a chemical is released that diffused across the gap. This causes an
electrical impulse to be generated in the second one.
, Human Reaction Time Required Practical - Ans>>1) the experimenter holds a meter
rule from the end.
2) the subject had their finger and thumb a small distant apart either side of the
ruler on the 50cm line.
3) the experimenter lets go of the ruler and the subject has to trap it.
4) the distance the ruler travels from the 50cm line is noted.
5) the experiment is repeated on the subjects that have just drunk coffee and the
subjects that have not.
Parts of the brain - Ans>>- Medulla
- Cerebellum
- Cerebral Cortex
Medulla - Ans>>controls automatic actions such as heartbeat and breathing.
Cerebellum - Ans>>coordinates movement and balance
cerebral cortex - Ans>>responsible for consciousness, intelligence, memory and
language.
Parts and Functions of the Eye - Ans>>- Retina - contains receptor cells that are
sensitive to brightness and colour of light.
- Optic Nerve - carries impulses from the retina to the brain.
- Sclera - forms a tough outer layer.
- Cornea - transport region.
- Iris - controls the size of the pupil and the amount of light reaching the retina.
- Ciliary Muscles & Suspensory Ligaments - change the shape of the lens to focus
light onto the retina.
Accommodation - Ans>>The process of changing the shape of the lens to focus on
near or distant objects.
Myopia - Ans>>Shortsightedness.
Hyperopia - Ans>>Long sightedness.
The Endocrine System - Ans>>This is made up of glands that secrete hormones
directly into the bloodstream.
Hormones - Ans>>Chemical messengers that are carried in the blood.
Pituitary Gland - Ans>>This is a master gland in the brain that secretes several
hormones in response to body conditions.
